What is the likelihood of a successful outcome with MIRP?
Parathyroid glands control the level of calcium in your body. There are four of them, two on each side of the neck behind the thyroid gland. Many patients confuse the word “parathyroid “ with “thyroid”. The only real connection they have to one another is their location in the neck. The “para-“ in “parathyroid” means “next to”, hence, the term simply means that the parathyroid glands are located “next to the thyroid gland”. I sometimes simply call them the “calcium glands” in order to avoid this confusion.
The four parathyroid glands are tiny when normal, usually about the size of a baby aspirin, located just behind the thyroid gland. They monitor the level of calcium in the blood stream. When the level of calcium is low, they are “turned on” to produce their hormone, PTH. This PTH (which stands for “parathyroid hormone”) causes your body to retrieve calcium back into the blood stream from wherever it can. If you have calcium in your diet, your bowels will increase their absorption of calcium. Calcium that has been deposited in the bones will be drawn back out into the blood. Once the calcium level has normalized, the PTH level drops back down.
In the normal situation, the calcium level remains balanced between about 8 and 10. The calcium in your bones stays put, and if you add calcium to your diet, it gets transferred to your bones or is filtered out by the kidneys without elevating the level of calcium in your bloodstream out of this normal range.
In some people, for reasons unknown, one of the four parathyroid glands becomes overactive, like an engine with the throttle running high all the time. In this case, the one overactive gland is always producing PTH, no matter what the blood calcium level is. The body responds by raising the blood calcium level abnormally high. In most cases, the calcium level in such cases will be just a little higher than normal, in the high 10’s, or 11. This level of calcium may not dramatically alter how you feel, in other words, you may be asymptomatic or only have subtle signs. But this abnormal calcium level can cause problems. It makes some people feel tired much of the time. It can cause some mild depression. It can cause or aggravate high blood pressure, and make it more difficult to get your blood pressure in a normal range with the usual medications. Your bowel function may slow down, causing constipation. Over time, the calcium can build up in the kidneys, and form kidney stones. Over a period of years, the buildup of calcium can clog up the filtration system of the kidneys, causing progressive failure of the kidneys. The continuous withdrawal of calcium from the bones can weaken them. In women who already suffer from osteoporosis or osteopenia, this situation just makes matters worse. If left untreated for years, the bones can become very abnormal, to the point that there are obvious changes that can be seen with simple xrays.
In the past, patients with this disease, called “hyperparathyroidism”, would not be diagnosed until these later stages of the disease, once the damage to the bones and kidneys had already been done. But now, calcium levels in the blood can be checked routinely with a simple blood test. If your calcium level is above normal, it is fairly simple to identify the cause. There are other reasons why your calcium level might be high, but a simple evaluation should make the diagnosis clear. If the high calcium level is because of an overactive parathyroid gland, a simple measurement of the PTH level will show a high PTH level, at the same time that the calcium level is high. If all the parathyroid glands are all functioning normally, the PTH level should NOT be elevated when your calcium level is high.
Since the high calcium level is detrimental to the body’s system over time, it is usually recommended to fix the problem. Currently there are no medications to correct it. But the abnormal parathyroid gland can easily be removed surgically, providing an immediate cure. In almost all cases, the problem is limited to just one of the four glands. Nothing needs to be done to the other three normal glands. In fact, the less we bother these other glands, the better off you’ll be.
For the past hundred years, the surgical treatment for hyperparathyroidism involved making a long neck incision under general anesthesia, and searching all the nooks and crevices in the neck around (and even inside) the thyroid gland, for all four parathyroid glands. The surgeon would then make a visual assessment of the four glands, to decide which one, or more, of the glands, were overactive. Biopsies of one or more of the glands would be done, to try to decide which glands to completely remove. In some cases, not all of the glands would be found, and in fact, it might be that the abnormal gland may never be identified.
The traditional operation described above was necessary in the past, because the surgeon had no way of knowing in advance which of the four parathyroid glands was the problem, or whether a particular patient was one of the exceptional cases in which there was more than one abnormal gland. But we now have some excellent localizing tests that can be done before surgery that are highly accurate. The most important of these tests is the sestamibi scan.
The sestamibi scan is named after the radioisotope used. It is the same radioisotope used for patients undergoing evaluation of their heart function. It works in both tests for the same reason—the isotope is taken up after injection into the bloodstream by the most metabolically active cells in the body. These cells are using large amounts of energy constantly. Less active cells do not take up much of the radioisotope. As a result, the scan that is taken shows focal areas or “hot spots” that show where the most active cells are. In the case of parathyroid glands, a single adenoma almost always shows as a “hot spot” on the scan, since it is a “high energy” gland. The other glands, which are in a resting state, will not show up. As a result, the scan can identify the single gland that is overactive. The surgery can then be directed toward identification and removal of a single gland. This is the basis for the less invasive procedure, called a MIRP, or “minimally invasive radioguided parathyroidectomy”.
Another useful test for localizing a parathyroid adenoma is an ultrasound. This test uses the same technology as is used in pregnancy to look at the baby developing in the womb. The ultrasound probe is placed on the neck, which shows the internal anatomy. Normal parathyroid glands are so small that they will rarely be identified with ultrasound. But an overactive gland will usually be large enough to be seen, as a distinctive dark, somewhat triangular shaped structure, just behind the thyroid gland. This test can be helpful in knowing before the operation what the size of the abnormal gland is, but it does not provide the same information as the sestamibi scan, which correlates more closely with overactivity in an individual gland.
These new tests have given birth to a less invasive surgical cure for hyperparathyroidism, the MIRP, or “minimally invasive radioguided parathyroidectomy”. With this technique, a small incision, only about one inch in length, is used. A sestamibi scan is done immediately before the surgery, so that the abnormal gland can be located using a special probe, just like a Geiger counter. With this technique, the surgical dissection is very focused and limited. The normal glands are left alone. As a result, the operation is usually completed in 30 minutes or less, and can be done without general anesthesia. Patients can usually go home the same day.
Complications during the procedure are uncommon, but you should be aware of these possible problems. Behind the thyroid, on either side is a nerve that activates each vocal cord in your larynx, or voice box. These nerves are quite close to the parathyroid glands, so it is possible for them to be injured during the surgery. If this happens, your voice is likely to be affected. With the traditional parathyroid surgery, there is a lot of dissection done very close to both of these nerves. Fortunately, even with the traditional operation, injuries to these nerves (recurrent laryngeal nerves) are uncommon. But with the MIRP, the surgery is limited to only the diseased gland, and specifically, to only one side of the neck. This focused procedure, which is usually almost bloodless, does not require dissecting the nerves, thus minimizing the risk of any injury or bruising. Excessive bleeding is a potential complication of any surgery, no matter how small or large the operation is. This problem is only very rarely seen with the MIRP, since the dissection is limited to finding only the involved parathyroid gland..
After the surgery, your calcium level usually normalizes in just a day or so. The level of the parathyroid hormone drops almost immediately. In fact, the other glands sometimes don’t become active quickly enough to keep your calcium level in the normal range. As a result, you may actually have symptoms from a low calcium level. These symptoms include numbness and tingling around your mouth and in your fingers, anxiety, or lack of energy. If you have these symptoms after surgery, it is a sure sign that the overactive parathyroid gland was removed. But if left untreated, your calcium level may drop even further, and cause more severe symptoms, such as cramping, and difficulty breathing. These symptoms are prevented by taking calcium temporarily.
Calcium can be taken in a variety of ways. Tums have lots of calcium in them. A glass of milk is another option. Calcium supplements are available at any drug store without a prescription. Most women, even without a parathyroid problem, would benefit from taking a calcium supplement daily. In tablet form, the usual amount recommended is 1200 mgs (milligrams), or 1.2 grams each day. This would be two 600 mg tablets daily. After parathyroid surgery, this amount would be a good dose for starters, to take for prevention of the low calcium symptoms. If you have some tingling even with this dose, then you should take some more. Occasionally a patient might need as much as 10 grams of calcium (that’s almost 20 tablets!) temporarily to get rid of the symptoms. But once the normal glands kick in, your calcium level will be maintained in the normal range without the need for supplements.
Parathyroid surgery is not a common procedure for most surgeons, simply because hyperparathyroidism is not nearly as common as other things that surgeons take care of, like hernias, gallbladder problems, and breast problems. As a result, many surgeons either don’t do any parathyroid surgery, or perhaps one every year or so. In their five years of training, they may have only actually seen just a few cases, and may have only done just a handful. They are likely not skilled in doing the MIRP, and in most cases will recommend doing the traditional bigger operation, under general anesthesia, with a hospital stay of one or two days. And if a surgeon only does maybe one of these operations a year, they do not have enough experience to know what their rate of success is. You should probably not allow such a surgeon to do your parathyroid surgery, when the outcome is so unpredictable.
There are still experienced parathyroid surgeons who recommend the traditional bigger operation for essentially all patients. Their reasons typically have to do with knowing that they have had good results with the bigger operation, in terms of curing the high calcium level, and worrying that a less invasive operation will possibly not cure the high calcium level. They may be unwilling to learn the new procedure, which requires new knowledge and skills. They may not have reliable sestamibi scans at their hospital, something that is critical in assuring successful outcomes with MIRP. But in experienced hands, MIRP has also been shown to be highly successful, with the added benefit of being much less invasive. So, you can have your parathyroid removed by the traditional large incision, under general anesthesia, and be admitted to the hospital, or you can have it done through a very small incision, under sedation and local anesthesia, as an outpatient, with the same expected outcome. Which will you choose?
The sestamibi scan, coupled with an appropriate pre-operative evaluation and an experienced surgeon, will almost always lead to immediate cure for hyperparathyroidism. At Dekalb Surgical Associates, we track our results for all parathyroid patients. Over the past 5 years, our success rate is 98%.. If you are seeing a surgeon for possible parathyroid surgery, you should ask how many procedures they do each year, and what their success rate is.
Call our office at 404-508-4320 to schedule an appointment. You will need to bring with you all pertinent lab results and scans. You may send them in advance if you wish. There is no fee for pre-review of your studies, nor is there any extra charge for your initial consultation, over and above the usual office consultation. If you have some general questions, you may email me at drkennedy@dekalbsurgical.com.